1. Field of the Invention
The invention relates to a lens holding frame for a camera lens system, in particular, one which is divided into front and rear lens system by a shutter housing.
2. Description of the Related Art
Camera lens systems have been known to include a front lens group for focusing. Such a front lens group is located in front of a shutter housing in such a manner that focusing is accomplished by axial movement at the front lens group. Such a lens system has been known to include a rear lens group arranged behind the shutter housing. A satisfactory optical characteristic can be obtained by setting the optical axis eccentricity accuracy of the front and rear lens group to 0.05 mm or less.
The optical axis eccentricity accuracy depends on adjustment of the components when assembled, or the dimensional accuracy of each component. However, it is difficult to increase the optical axis eccentricity accuracy to a desired value because a relatively large number of components are employed and because the desired value is relatively high. In general, the rear lens group of the camera lens system is made up of plastic lenses because such lenses can be readily molded and because the required lenses are intricate in configuration. The optical characteristic is lowered if the stress-strain or the play of the lenses caused by thermal expansion or contraction of the lenses is not absorbed.
An object of this invention is to provide a lens holding frame for a camera in which the optical axis can be readily adjusted, and in which the stress-strain or the play of lenses caused by thermal expansion or contraction of the lenses can be absorbed.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out in the appended claims.